10 Dollars - Elizabeth II Montserrat Oriole

The Montserrat Oriole exists on a single island whose habitable land shrank dramatically after the Soufrière Hills volcano resumed erupting in 1995, burying the capital Plymouth under pyroclastic flows and rendering the southern half of Montserrat an exclusion zone to this day. The bird's entire wild population — confined to the Centre Hills — was estimated at fewer than 300 individuals by some surveys in the 2000s, making it one of the most geographically restricted species on earth.

The Eastern Caribbean Central Bank issues these one-ounce gold pieces as legal tender across its eight member territories, though Montserrat itself has a population of under 5,000.